[arch-general] Mariadb eats system ressources

[rumpelsepp at sevenbyte.org]

Hi,

after struggling with this problem for one week I have finally decided
to post on the arch list for getting some help. I have a very strange
problem with mariadb from the official repos.

I run a usual LAMP stack (apache, php-fpm, mariadb) on archlinux. Since
one week (or so) I have realized a very strange behavior: One mariadb
process stucks on 100 percent CPU usage. I am not able to figure out
what's going on. Restarting mariadb fixes the problem for a few hours.
Here is a list of a few debug outputs [1]; I have put it in my pastebin
because my email client would wrap the text at 80 chars. If you need
even more information I can update the paste.

The mariadb status page shows about 6,5 queries per second (!) and I
don't know where this comes from. I have disabled remote access with
"skip-networking" (mysql port is closed) and the PROCESSLIST does only
show one process. I thought it might be an DDoS attack on a website but
no apache access-log grows unexpectedly. Even after stopping apache
mariadb stucks on 100 percent cpu usage.

I figured out that there are listed a lot of connections in the output
of "show status like 'Con%';". Last hour I even had about 5000
connections but there are no appropriate queries visible in the general
log. The general log lists the wordpress queries which are executed when
I click on my homepage. Everything looks fine; the cpu usage does not!
Do you have any ideas what I can do to figure out what's going on with
my mariadb? 

Thanks in advance!

Stefan 

[1]: http://snippets.sevenbyte.org/8/raw/